Typewriting machine



f mg.. 5, 11924.

L. A. NEMCOVSIKY TY PEWRIT ING MACHINE Filed June 26, 1923 2 Shams-Sheet l 1N VENTOR ugo ll y SW3 L. A. NEMCOVSKY TYPEwRITiNG MACHINE Filed June 26. 1923 2 @ww-Sheet 2 f5.1@ ma im ATToRNEx/.

Patented Ang.. 5, mdd..

fifi rita Louis a. nniacovskv, or :new vonk; rr. r.

TYPE'WRITING MACHINE.

Application led June 26, 1923. Serial No. 647,776.

T o all whom z't may concern Be it known that I, Louis A. NnMoovsKY, a citizen of the United States, and resident of New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in `lypeivriting Machines, of which the following is a specification.

My presentnv'etion relates to typewriting V.machines and is more particularly concerned with the type action thereof.

They invention has among its objects to provide a type action, eecting sharp imrecord speeds substantially without possi-- bility of binding or. jamming of typebars,

and the various elementsofwhich can be easily produced with the use of few dies and l easily assembled without substantial expense for skilled mechanical labor. Y.

Another object is to provide a type action of the above character, which occupies little space vertically of the machine, and therefore, lends itself readily to low and compact, so-called portable typewriting .machines, and, in fact, may occupy so little height as to afford ample room even in the low portable non-collapsible machine for the relatively wide segment plate used with the Vdesirable standard four-bank keyboard.

ln the preferred low standard keyboardA typewriter, the key levers extend from the keyboard in familiar parallel relation, substantially thev depth of the frame and the wideI segment plate forthe forty-two or more type barsl is disposed quite low, the middle or Ilowest point of the type bar bail thereon being substantially at the upper limiting level of the key levers. The type bars pivoted upon the ballare of uniform length extending in 'substantially parallel relation with their widths radially of the segment plate in' accordance with approved desk typewriter practice. vThe connecting linkage froml the key levers to the type bar heels occupieslittle s ace otherwise useful, said linkage being disposed largely in the space' between the key levers and below the upper edges thereof.

The linkage comprises preferably a sys-A lel -tem of bell. crank levers pivoted in para planes about a 'common horizontal trans- 60 verse axis, the upper ends of the rearward arms of said levers radiating inward in a plane substantially parallel to the segment plate and substantially to the radial plane of movement of the respective type bars and @5 extend to substantially the level of the heels thereof to which they are connected by a system of links. pact printing with an extraordinarily light Connecting links Abetween the bell crank levers'and the type bar heels are preferably 70 in substantially parallel relation, at right angles tothe segment plate, at an obtuse angle relative to the radiating bell crank lever arms, and at an acute angle to the type bar heel axis, said obtuse and acute' angles both 75 .approaches more nearly a right angle when the` type head strikes the platen. The lengths of the links thus move .in the-general direction of displacement of the points of anchorage thereof to the respectiveb'ell 30 crank lever and type bar, so that the operative force applied at the key levers is effec-- tively transmitted by substantially direct tension through the links to the type bars.

The operative connection between the ke 95 levers and the bell crank levers isth'roug a camming connection, which, in the preferred embodiment, comprises an inclined slot in the lforwardly inclined arms of said levers and corresponding ins movable with the key levers and extending `into said slots. In the operation of each 'key lever, the corresponding pin is arranged to advance progressively along the length of the slot in a single direction, the pin reaching -a limiting position at a level no lower than the pivot point of the bell crank lever, when the type bar strikes the platen. By this arran ement, it follows that for uniform rate .of epression of the key lever, the bell crankle- B500' vers have an 4angular acceleration''- which reaches its maximum at the end of the stroke and which is transmitted through the qlinkto the corresponding type bar heel, to impart a similar acceleration to the type bar for wil edective impact printing.

To compensate for the frictional losses which increase progressively from the type bars at the middle to those at the ends of the segment plate, the pin and slot or other il@ position of the machine being near the outer ends of the associated slots, the pins of the central keys nearer theinner ends ofthe associated slots and the pins of the intermediate keys being at intermediate positions relative to the lengths of the correspondin slots, so that for the lateral keys, the initia movement of the key lever pin will be more nearly in the direction of the slot to produce' relatively small initial movement or relatively high initial mechanicaladvantage, so as to impart sutiicient momentum to said linkage to overcome the greater friction thereof, as compared to the linkages for the other keys, for each of which the initial mechanical advantage will be in accordance with the friction thereof.

In the preferred application of the linkage and particularly in the low portable machine described, the bell crank levers constitute a system of sub-levers pivoted at a common axis below the key levers and preferably substantially at the very bottom of the frame, and the links slope upward from the type bar heels to the ends of the rear arms of the sub levers. The lowest or central part of the type bar supporting bail preferably extends substantially to the level of the key levers for compactness. To accom modate the combined width of the type bar d heads which is, of course, greater than the corresponding length of the bail, the rest is struck along an arc larger than and inra plane parallel to that of the bail, but from a center relatively higher than that of the bail, where a concentric or Coaxial type bar rest would entail corresponding elevation of the segment plate above the preferred lowest level, adding to the height and bulk of the machine.

In the accompanying drawin s in which is shown one of various possi le embodiments of the several features of this invention,

' Fig. 1 is a plan view of a typewriting machine with all parts removed above the type action, most of the type bars and links being removed to better 'reveal the construction,

i Fig. 2 is a fragmentary sectional view transversely of F ig. l,

to printing position.

neoaeoo Fig. Bois a sectional view illustrating the linkage or type action for one of the end ke s, showing the printing position in dotte lines,

Fig. 4 is a view similar to Fig. 3 indicating similar relations for a key substantially at the middle of the machine,

Fig. 5 is a perspective view of the sublever of Fig. 3,

Fig. 6 is a view similar to Fig. 5 of the sub-lever of Fig. 4c, and;

Fig. 7 .is a detail view showing the precise construction of the cam end of the sub-lever.

Similar reference characters refer to similar parts throughout the several views of 1' the drawings.

The present application is a continuation in part of my copending application, Serial Noj 589,571, filed September 2l, 1922.

Referring. now to the drawings, I have shown the frame or casing 10 of a typewriting machine havin a cross-bar 11 at the rear thereof, stra dled by the usual stamped metal angle plate 12 which is secured as by screws 13 to the side frame of the machine. A system of key levers le are pivoted at theirrear ends in corresponding notches 15 in the lower edge of the angle bar and extend parallel to eachothen forward therefrom, all being normally maintained by coil springs 16 raised to a uniform level against horizontal stop edge 17 in the forward end of the enclosing casing l0. The mechanism, as shown, has 42 levers terminating at the forward end` in the usual standard 42 key, fourebank ke board best shown in Fig. 1, there being t e standard difference of level between the consecutive banks.

Thesegment vplate 18v is secured to the frame of the machine by screws (not shown) and is shown extending through the arc customary with desk machines of about 114; egrees, and ismaterially narrower than the key lever system as appears in Fig. l. The type bars 19 -have hooks 2() straddling the usual arcuate support rod or bail 21 which extends conoentrically about the segment plate 18, the segment having radial slots which the type bars enter in their movement The hook 20 has a 4straight shank edge 22 at right angles to the surface of type 25, said shank fitting snugly between the universal bar 23 mounted on the segment plate and the bail, when the type strikes the platen, thereby assuring alignment of the type. The type bar is curved as at 24 at the part thereof which operates the universal bar, for direct surface engagement with the edge of the latter.

lli-the present embodiment, particularly to a'ord a low and compact machine, the middle or lowest point of the bail 21 extends substantially to the upper level of the key lever system and the segment plate 18 is,

monaco moreover, inclined rearward at an angle referably of about 2O degrees, the platen being movable for case shift in a plane. parallel to the segment plate by a shift mechanism not here shown, but full described in my copending application. l erial No. 589,571, filed Sept. 21, 1922.

rlhe tvpe bars, as is usual in desk type writing machines, extend with their widths radially of the segment plate and are of uniform length with the type heads thereof, bent at different Aigles, so as to compensate for the diderent inclinations. of their planes of movement to print vertically at the platen, the lengths of the type bars extending parallel to each other and to the key levers and in cumbent position, being supported upon arcuate rest 26. The type bars in the present embodiment are but slightly shorter than the standard length of type bars, this length being preferably 3l, and the minimum angle of movement thereoi` from rest 26 to laten 24- is about 95 degrees.

rlhe linkage etween the key lever system and the associated type bars, comprises a system of bell crank sub-levers 27 pivoted about a horizontal transverse rod 28 anchored in a bar 29 at the bottom of the frame and nearV the front or the casing, the forward arm 30 of said various sub-levers being actuated from the associated key levers by means to be described below. The rearward arms 31. of said sub-levers, as besty shown in.y Figs. 2, 3 and d' radiate inward, each from a bend 32 abovethe contiguous parte of the key levers, to substantially the radiating" planes of the corresponding type hars, with their-lateral edges 33 in a common plane substantially parallel to the segment plate k18, each said rearward arm 31 having a short ti 34 bent inward as at 35 and extending su' stantially in the plane of the corresponding type bar. rlhe connecting pitman links 36 which may be ot" wire, are simply hooked at their forward ends in corresponding holes or eyes 37 in the sublever tip 3l at their rear ends, and in holes or eyes 38, all identically positioned in the type bar heel 39. As shown, the tip 34C oi each sub-lever is at a level somewhat higher than the link anchor eye 38 of the corresponding type bar heel, so that the link 36 s opes Upward from the type bar heel. The linkin non-operating position is at an obtuse angle with respect to the corresponding sublever arm and at an acute angle with respect to the type bar heel lever arm, as shown, both said angles approaching more nearly a right angle as shown in dotted lines when the 'type bars strike the platen, for purposes which will appear hereinafter.

its the type heads take up more space laterally in cumbent position than the type bar heels on the bail, the length of arcuate rest 2li must be correspondingly greater.v c-

cording to my invention, the rest extends along an arc in a plane parallel to and of diameter larger than that of the bail, but st-ruck from a center higher than the central perpendicular to the plane of the bail, the specific proportions of the desirable model constructed b v me being illustratively indicated upon the drawings. Thus, l provide 4an arc rest sufficiently long to accom modate the type heads, and which yet permits the disposal of the bail 21 at the low level shown and heretofore described. It the rest extended along an arc of larger diameter than that of thebail, but concentric y or coaxial therewith, then the segment and bail would have to be elevated from the position shown, increasing the overall height or bulk of the machine. By reason oi the eccentricity of the arcuate rest relative to the bail 21, the angles of throw of the type bars are not strictly uniform, the central bar moving in the specific embodimenty shown through a range oi about 95 degrees, as heretofore noted, the extreme lateral keys through la somewhat greater range of about 100 degrees. the range of the intervenin type bars beingl vgraduated between sai limiting ranges. By reason of said eccentricity. the link anchor eyes which are pov sitioned in identical relation on each of the identical type bars, do not extend in a plane precisely parallel to that of the bail, and it is preferred to dispose the common plane of the radiating sub-lever edges 33 in curou bent position of the type bars parallel to the locus ot' eyes 38, so that the connecting links 36 will obvioushT be of equal length and Substantially parallel to eachy other.l

Referring now particularly to Fig. 4 which shows the type action associated with the longest of the group of key levers midway between the two sides of the machine` the associated type bar 19 substantially midway between the ends of the segment plate-is at correspondingly lowest level, and, as shown, extends into the space provided bythe downwardly curved rear end 40 of the key lever. The forward arm 30 ot the sub-lever is con,- nected with the key lever 14cm by a camming connection, preferably comprising a pin l1 projecting from the key' lever and entending into a slot 44 in the forward arm of the sub-lever. The slot. as best shown in Fig. 7 comprises a curved outer end, the median line' of which is struck on an arc lig in diameter from a center, which is from the pivot axis along` a line at anangle of 45 degrees trom the connecting line (t-a between the eye 34 and the base of shank 33. The slot, as shown, has a. straight lower or inner portion 43 extending in the specific embodiment shown longitudinally of the arm, at an angle of 36 degrees with respect to the horizontal and tangent to the curved slot 44. 'As shown, the construction of icc ire

straight slot 43 passes above the pivot axis..

The pin l1 in the cumbent, inactive or normal position of the type bar is well within the slot, as shown, only littlel above the termination of the straight portion 43 `of the slot. The line joining the` eye 37 to the pivot pin Q8 is preferably substantially vertical in the central key 14m. 4 As key 14m is depressed, the pin 41 in its movement about p-ivot 15 as an axis moves longitudinally inward along slot 44-13 and rotates sublever 30 about its axis 28, drawing on the link -36 to move the type bar 19m about its pivot 21 as an axis to platen impact, indicated in dotted lines. lVith the parts constructed, as shown, the impact of the type bar with the platen occurs when the sublever is in the extreme dotted line position, in which, Ias will be noted, the pin 41I is no lower than the plane of the pivot rod 28 and 'preferably as indicated, somewhat higher, and has a small clearance with respeet to .the inner end of slot 43.- It will vthus be seen that in this operation, as th'e finger depresses the key, the movementof the p-in approaches more nearly a direction at right angles t0 that of the slot 4?44 as the downward movement progresses, so

that the effective' force upon the sub-lever and correspondingly the angular velocity thereof increases to a maximum at the end of the stroke. The forward anchor 37 of the link moves upward with. the rear arm of the sub-lever through only the small range shown. in the forward advance to the dotted line position, while the rear anchoring end 38 of said link moves downward with the type bar heel, through only a small range inthe pivotal movement of the latter,

the movement of the link throughout its paith being thus nearly in the direction of its length, soA that the angular acceleration of the sub-lever effects a corresponding translational acceleration of the link or pitman, which produces a corresponding angular acceleration of the type bar for substantial vimpact with the platen to produce sharp clear print.

Referring now to Fig. 3 which indicates one of the extreme lateral type bars associated with the shortest key lever 14l of the associated group, the sub-lever is identical in construction with that shown in Fig. 4, except that the rear arm. is substantially longer and bent as at 32 and 35, as previously noted, to dispose its tip substantially in the plane ofthe relatively elevated heel of type bar 19. `The length of the inwardly bent shank 31 extends in a plane substantially parallel to the segment plate so that the link 861 is of the same length as link 36r for .the central type bai-and eX- tends parallel thereto, as previously noted. As type bar 19 must move through substantially the same angle asr type bar 19m from cumbent to platen striking position, the link end 37m, must move through the same linear range as the link end ,371 in Fig. .4. As, however, the lever arm 311 is very much longer than lever arm 31m, it follows that the angular displacement of the sublever 801 should be through a correspondingly smaller range, also as thetype bar moves in a plane inclined through a large angle to vertical, the friction to be overcome in operatioi'i is high 'coi'npared to that for the central keys. Compensation. both for the dili'ercntial sub-lever displacement and for the differential friction is achieved by the simple expedient of disposing the pin il on the corresponding key lever li4 near the mouth or outer end of the slot it. It follows .that when the key lever is depressed through its full range, which is preferably the same for all key levers. in the present instance Tit. the arc of movement of the pin at the outset is along a line at a small angle to the corresponding length of slot.l so that the sub-lever is deflected but. little or slowly at the outset even for relatively quick key depression and, in fact. throughout substantially the first half of the key stroke. Thus, for the extreme lateral keys where the friction is substantially higher than for the central keys. the type action is displaced only a little for a substantial fraction of thc key lever stroke from the outset. 'The key lever may thus acquire substantial speed in the consequent light initial load` affording momentum to overcome the friction on the linkage as the latter is actuated through the greater part of its displacement during the last half of the key stroke. The. angle between .pin movement and slot. length increases as the depression of the key lever continues, so that a correspondingly increasing component of the force on 'the key directly :1pplied upon the linkage. as the stroke progresses to produce accelerated movement of the linkage to a maximum speed when the type bar strikes the platen, that is. when thev pin reaches the extreme position shown in dotted lines where it still has clearance with respect to the inner end of .slot 43. ln other words,l the lateral keys afford a relatively quick and relatively frictionless start to overcome the greater friction and loud thereon through the main part. of the af celerated linkage displacement. The operation throughout in Fig. 3 is` moreover. at

a higher mechanical advantage than in Fig.

l and the angle of displacement: of the sublevers in the former is correspondingly less,l as shown.. to produce the uniform type bar displacement. noted.

The intermediate keys, that is. those botween the central keys shown in Fig. t and the extreme lateral keys shown in Fig. 2, all have sub-levers, the forward ends of Utl llt)

which extend at the constant angle noted and all of which have identical slots, ekactly superposed when viewed from an end of the machine, the pins t1 tor the intermediate key levers being located at points on the key levers intermediate or Ilaetnveen the extreme points noted in Figs. 3 and 4, the

ln each case, of course, it Will be seen that theangle of displacement of the forward `arm of the sub-lever, :tor moving the type bar from cumbent to platen striking positiomwould be ascertained, and the range of r displacement of the pin on the correspond- I ing key lever through an arc Withthe rear f plate 15 as its center," would be through a distance less than the stroke of the key in proportionv as the.v distance from the pin to `the key vlever pivot is less than the overall length of the key lever. The position of the pin on eachlever would thus be easily ascertained trio'onometrically or graphically.

l have 2built an operative model embodying the specific construction of sub-lever 'shown in Fig. 7 with the rear bank of keys upon levers 5% inches long from pivot to the key and theorward lbank of keys with f levers 7 t inches long -from the keys thereof to said pivot, and the pivot shatt 413 inches.

in `iront of the common pivot. For typevvriting machines of different proportions, the sub-levers and the location thereof may,

.ci course, be modified Within the scope of the invention in manners apparent to those skilled inthe art. I

The mechanical advantage ot operation between the key lever and the sub-lever at the outset of the key stroke is a minimum for the central keys and will increase progressively to a maximum for the extreme outer keys. The rangeo'l an ular displacement et the sub-lever which 1s a maximum for the central and a minimum for the lateral keys, will be graduated between these limits, for the intermediate keys,` by the positions of the pins 41, to produce the uniform angular displacement of the corresponding type bars, there being' produced in each case, sufficient momentum of the key lever preparatory to the final maximum load or speed of the linkage to com ensate for the friction in the linkage whic increases progressively from the central keys to the extreme llateral keys.

. For eachy ot the keys, the in 41 at the extremity of its operative stro e, still leaves clearance with respect to the inner end ot slot 4:3, which edects automatic compensation tor wear in the' thickness of the type `or in the adjustment ot the platen mount,

and which 4 recludes the possibility of jamming, whic might sometimes ensue if a pin were free to move to the inner extremity ot the corresponding cam slot.

lt will thus be seen that the touch of the various keys is substantially uniformly light, the extreme lateral keys providing a touch no harder than the central keys and this, even though the return springs 16 are all of uniform strength. In other words, I have provided a .type action in which the touch even of the extreme lateral keys is as light as that of the central key, avoiding the need for specially loadiniror` tensioning the various springs 16. 'he latter arrangement would retard the speed of the machine and make its touch harder since the operation of each key there is as hard as that of the stidest ke With the type action set forth, particularly in constructions otherwise identical to those shown in my copending applications, Serial No. 589,571 above referred to and Serial No. 607,766 liled Dec. 19, 1922, l have been able to easily exceed the s eed perfomance et any other known mac ine tested under the same conditions Aot operation.

lit will also be seen that in my t pe action by reason of the substantial y continuous acceleration of the type, particularly in the last halt of the key stroke, the t pe bar will advance through a small angle uring the first two thirds of the stroke, traversing the last 60 degrees ot its 95 to 10G degree stroke, during the last third ot the key stroke. By this sharp acceleration to a maximum s eed at platen impact, l pro duce not only s arp print with many carbons, but the type bar returns so rapidly trom the laten, almost the instant the key is released, that the possibility oi interlocking of type. bars is substantially obviated. its a matter ot Ytact, it will be practically necessary to strike two contiguous keys practically simultaneously to produce conict, substantially the smallest time interval between the striking ci two'keys being sucient to cause the former to return out ot the ran e ot interlock with the latter. llt follows t at .at the highest speed ot operation attainable even by most expert speed operation, jamming or interlocking of the type bars is substantially precluded.

.hs heretofore pointed out, the obtuse anle that the sub-lever arm forms with the ink 36 and the acute angle of the type bar heel with said link, both approach more nearly a right angle in the case of each key, as the laten is struck. rlhe pressure is lthus eoiently transmitted from the key lever through the linkage to the type, to produce not only the high impact speed previously noted, but high impact Apressure lor Mill llO

producing a multiplicit of clear carbon copies in addition to t ev sharp original. This is to be distin uished from constructions in which two s. assume a relation of substantial alignment with respect to each other as the type strikes the platen, in which case, the force is' inelticiently applied at least as.regards pressure .on the platen, which may be but a small fraction of the manual force applied at the keys.

The central plane of the support bail is preferably tangential to the platen 24 at the end of diameter d-d thereof, which diame` ter is at right angles to the line of shift displacement, as best indicated in dotted lines in Fig. 4. The type 25 on each type bar is preferably arranged to strike at the end of said diameter d-d, upon the platen, and thus-moves strictly normal to the laten surface at the point of impact, pro' ucing uniform pressure at the top and bottom of the letter. rlhe strai ht hook on the type bar prevents minute s ifting thereof in the space between the bail and the universal bar, so that the typed product is accurately aligned. The ty e bars, as is apparent, are readily and in ividuallyl removable from the machine and readily replaceable, so that a new type bar can be easily substituted Jfor a worn one,without need for disassembly of the machine in part.

It will be seen that the construction of the machine in its entirety comprises a type bar mechanism of low construction inwhich the lower end of the bail for the type bars is substantially at the upper stop level of the key levers, and all of the type action linkage is below the said type bar bail. lt follows that even thou h, a wide segment plate of standard spread of 114 `degrees is used, yet by reason of the low position of the type bars, the overall hei ht of the machine still remains quite low. h e segment plate rcnders posslble the use of 42 or more keys of the standard keyboard, and type bars of substantially the standard length customarily used `with desk typewriters, which keys move through but the relatively small angle of'95 to 100 degrees in operation.

By the inclined construction of segment plate, the overall height of the machine is still iurther reduced 'and ample room is aorded therebehind by reason of the compact low construction of the type action for the universal barQB mounted on the segment plate and for the escapement, ribbon shift and other accessories (not shown)` which are preerablydisposed in the space between the inclined segment plate and the rear of the machine, allsaid elements being constructed and arran edin. the manner best shown in my copen ing application, heretofore referred to.

It will thus be seen that there is herein dihed apparatus in which the several features of this invention are embodied, and which apparatus in its action attains the various objects of the invention and is well suited to meet the requinments of practical use.

As many'changes could be made in the above construction and many apparently Widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all mattercontained in hthe above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sznse except as limited by the claims.

I claim:-

1 4In a typewriting machine, in combination, a casing, a system of key levers pivoted at their rear ends, an inclined segment plate narrower than said system oi' key levers, type bars pivoted with their Width radially thereof and extending substantially parallel to each other and displaceable in planes radially of said segment plate,\a linkage system connecting said key levers to sai type bars, each said linkage system inclu ing a camming connection affording a mechanical advantage of operation co-related with the length of key levei` and the an lar relation of the type bar for substantia ly uniform touch of all the keys and further including pitman links of uniform length.

2. In a. typewriting machine, in combination, a casing, a system of key levers pivoted near the rear of the casing and terminating in a keyboard in front, a segmerit plate narrower than said system of key levers, a bail thereon, type bars pivoted on said bail, extending parallel to cach other and displaceable along planes radial. of said segment plate, linkage systems connecting said key levers to said type bars, each said linkage including a connection embodying a curved camming guide said guides substantially identical in size and shape and an operator in which the path of movement of the operator relative to the l'ngth of the vguideis at an acute angle, increasing as the stroke progresses to a maximum at the end o the operative stroke, each said cam operator being correlated with respect to the corresponding key lever and type bar for uniform lightness of touch.

3. n a typewriting machine, in combination, a casing, a system of pivoted key levers having uniform key stroke, a segment plate narrower than said system of key levers, a

vbail thereon, type bars pivoted to said bail extending parallel to each other and displaceable in planes radial of said segment late, linkage systems connecting saidkey evers to said type bars, said linkagesincluding a system of bell crank levers pivoted'on a common horizontal axis and having identi- Lacasse cal curved eamming guides in the forward arms thereof.

4. ln a typewriting machine, in combination, aeasing, a system of key levers having uniform key stroke and pivoted near the rear of the casing and terminating in a keyboard in front, an inclined segment plate narrower than said system of key levers, a bail thereon, type bars pivoted on said bail, extending parallel to each other and displaeeable along planes radial of said segment plate, linkage systems connecting said key levers to said type bars,- each said linkage including a connection embodying a curved camming guide, said guides substantially identical in size and shape, and an operator in which the path of movement of the operator relative to the length-of the .guide is at an acute angle, increasing as the stroke progresses Lto a maximum at the end of the operative stroke, each said cam operator being correlated with respect to the corresponding key lever and type bar for uniform lightness oftoueh.

5. ln a typewriting machine, in combination, a casing, a bank of parallel key levers terminating in a keyboard,'a segment plate, a bail curved thereabout. having the middle i or lowermost portion of the are thereof at substantially the level of said key levers, type bars pivotally mounted upon said bail, and transmission linkage interposed between each key lever and the corresponding type bars; each said linkage including a bell crank, lever having an upwardly inclined arm, extendingbelow the upper level of said key lever for operation therefrom by a pushaction and a tension link pivotally attached to the heel of the type bar and movable by a substantially simple tensile action from said bell crank lever in a forward direction.

(i. In a typewriting machine, in combination, a easing, a set of parallel key levers having uniform keystroke and vterminating in a standard keyboard at the forward end thereof, a segment plate, a bail curved about said segment plate with the middle or lowermost portion of the are thereof substantially at the level 0f the upper edges of said key levers, type bars mounted on said bail having the widths thereof extending radially of said segment and thelengths thereof parallel to each other and to said key levers, a set o1* `hell crank .levers mounted on a common straight horizontal pivot axis transversely of the machine below4 said key levers and near the bottom of the machine, said bell crank levers having upwardly inclined forward arms actuated from said key levers, rearward arms extending in vertical planes 'io points above the key levers and thence directed inward with their edges at a plane parallel to said segment plate and in advance thereof, each said arm terminating at substantially the level of the corresponding 'type bar carrying two types, the middle or lowermost part of the are of said bail being substantially at the level of the upper edge 0f said key levers, linkage connecting said key levers to the corresponding type bars, said linkage comprising a set of bell cra-nkv sub-levers having a common horizontal pivot axis near the bottom of the machine belowthe key bears with upwardly inclined forward arms terminating near the front of the easing and operatively associated with the key levers to be actuated thereby, the rear arms of said sub-levers extending in vertical planes to substantially the level of "the key levers, and radiating inward above the key levers each to substantially the radial plane of the associated type bar with the edges of all said inward radiating elements parallel to said segment plate, and a system of parallel links of uniform length connecting the type bar heels to the outer ends of said' sub-lever arms.

8. ln a tyl'iewriting machine, in combination, a casing, a system of straight parallel key levers pivoted along a common horizontal axis near the rear of the easing and. terminating in a standard keyboard at their forward ends, a segment plate inclined rearwardly, a bail about said segment plate with its central or lower portion substantially atthe level of the upper edges of the key levers, a system of eumbent type bars of substantiall)7 standard length, each with two types and pivoted about said bail with their widths along radial lines of said segment plate and their lengths parallel to each other and to said key levers, and transmitting linkage between the key levers and the type bars, said linkage comprising bell crank sub-levers pivoted near the bottom of the machine with forwardly extending arms terminating near the front of the easing, each having a camming connection with respect to the associated key lever and pitman links of uniform length connecting said sub-levers te the type bar heels.

9. The combination set forth in claim 8 in which the segment plate slopes rearward at an angle of ai'iproxin'lately 2O degrees and in which the angular range of displacement ef the type hars is approximately 95 degrees.

l0. In a typewriting machine, inl combi-y centric with said segment plate, a s et of cumbent type bars pivoted thereto of equalv length, the lengths of saidtype bars extending parallel to each other and the width of each in the radial plane of the segment plate, said type bars each movable through a range of substantially 95 degrees, from cumbent to platen striking position, parallel key levers pivoted near the rear of said frame, each key lever having an associated bell crank transmitting` sub-lever pivotally mounted therebelow, each said sub-lever having a rearward arin bent inward toward the approximate plane of the heel of the corresponding typehar and a link connect-a ing each said sub-lever to the corresponding type bar. 11. In a typewriting machine, in combination, a casing, a system of parallel key levers, a segment plate having a' bail thereon, type bars'pivotally mounted' on said bail with their lengths extending parallel to each other and to said key levers and their widths radially of said segment plate, connecting linkage between said key levers and said type bars, said-linkage including bell crank levers mounted on a common axis having their forward. arms actuated from said key levers andhaving rearwardly extending arms radiating inward in a common plane substantially parallel to said 'segment plate, each to a level substantially that of the corresponding type bar heel, the tips of said radiating yarms being bent each to substantially the plane of movement of the corresponding type bar and a system of-connecting links of equal length pivoted at opposite ends respectively to said tips and to said type bar heels for low friction transmission of key lever thrust to the type bar. '12. In a typewriting machine, in combination, a casing, a system of -key llevers having uniform key stroke and pivoted near the rear of the casing,'a segment plate narrower than said system of key levers, type bars having their lengths extending substantially parallel to each other and displaceable along planes radial of said segment plate, linkage systems connecting said key levers to` said type bars, said linkage including a system of bell crank sub-levers having a coin- 'inon horizontal pivot axis, the forward arms of said sub-levers having curved camming guides for said key levers, said key levers having portions rigid therewith coacting directly with said camming guides.

In a typewriting machine, in combination, a casing, a system of pivoted key levers terminating in a keyboard, a segment plate narrower than said system of key evers, type bars pivoted with their widths radially thereof and extending substantially n linkage systems connecting said key -par'aliel to each other and to said key levers and displaceable in planes radial of said segment plate, a linkage system connecting said key levers to said type bars, said linkage system including bell crank levers having a common horizontal fulcrum axis, a camming connection between each keylever and the corresponding sub-lever, said connection including curved slots uniform in proportions throughout the system.

14. In a typewriting machine, in combination, a casing, a system of key levers pivoted near the rear of the casing and terminating in a keyboard in front, an inclined se ment plate narrower than said system o key levers, type bars having their lengths extending substantially parallel to each other and to said key levers, and displaceable along planes radial of said segment 1plate,

evers to said type bars, said linkage including a system et' bell crank sub-levers having a common horizontal pivot axis, said linkaofelalso including pitinan links of uniform ength connecting the rear arms of the bell crank evers to the heels of the corresponding type ars.

l5. In a typewriting machine, in combination, a casing, a system of key levers pivoted .near the rear of the casing and terminating in a keyboard, an inclined segment plate narrower than said system of key levers, type bars pivoted with their widths radially thereof and extending substantially parallel to each other and to said key levers and displaceable in planes radial of said segment plate, a linkage system connecting said key levers o said type bars, saidlinkage system including bell crank levers having a common horizontal fulcrum axis, a camming c0nnec- 105 tion between each key lever and the corre spending sub-lever, said connection including curved slot-s uniform inA proportions throughout the system.

In a typewriting machine, in combi- 11o nation, a casing, a system of key -levers pivoted` near the rear of the casing and terminating in a keyboard in front, a segment plate narrower than said system of key levers, type bars having their lengths ex- 116 tending substantially parallel te each other and to said key levers and displaceable along planes radial of said segment plate, linkage systems connecting said key levers to said type bars, said linkage including a 120 systen'i of bell crank sub-levers having a Vconnnon horizontal pivot axis, said sublcvers having oblique forward extending arms, each having a camming connection with respect tol the associated key lever 125 i'or accelerated displacement of the type bar toa maximum speed at the end ofthe stroke, said bell cranks having rearward extending arms of variable length, each terminating at a level 'substantially that of the corre- 13o spending type bar heel, each said camming connection being correlated with the length of the associated key lever and the elevation of the associated type bar.

17. The combination set forth in claim 2 in which the camming connections include identical cam structures for the various linkages and the cam operators coacting therewith have initial positions lengthwise of the associated cam guide, correlated with the length of the key lever and the height of the type bar corresponding thereto.

18. ln a typewritingmachine, in comblnation, a set of parallel key levers pivoted near their rear ends, each having a return spring to maintain it in its uppermost position, .a segment platenarrower than said levers, typeV barspivotally sup orted therefrom with their lenhs exten ing substan- .tially parallel to eac other and to said key levers and movable in planes radialof said segment plate, linkage connecting said key levers and said ty. e bars, the linkages for the various type ars including a set of identical lever arms pivoted about a common horizontal axis, said lever arms having identical camv guide constructions and operator pins on the key levers coacting with said cam guide constructions, each operator pin initially at a point on the `cam guide construction such that .the type bar reaches platen Vstriking position at the end of the key lever stroke and` that the mechanical advantage of operation, near the beginning of the stroke progressively increases from a minimum for the mlddle keys to a maximum for the extreme lateral keys to compensate for the corresponding inherent differences in friction, whereby the touch of the various keys willv be substantially uniform.

19. In a typewriting machine, in combination, a set of parallel key levers pivoted at their rear ends, each having a return spring to maintain it in its uppermost position, a segment plate-narrower than said levers, type bars pivotally supported therefrom, with their len ths extending substantially parallel to each other and to said key levers and movable in planes radial of said segment plate, linkage connecting said key levers and said ty e bars, the linkages for the various type ars including a set of identical lever arms pivoted about a common horizontal axis, said lever arms having identical slots normally inclined forward, operator pins yon said key levers extending into said slots, each at a part of the length of the slot correlated with-the length of the corresponding key lever and the position of the corres onding type bar such that the latter reae es laten striking position at the end of the ey lever depression,

said pin at key lever depression being no' lower than the pivot of said lever arm,

whereby for uniform rate of depression of any key lever, the transmitting lever will have an angular" acceleration continuous to a maximum at the end for corresponding acceleration of the type bar to strike the platen at maximum speed.

20, ln a typewriting machine, in combination, a casing, a system of parallel key levers pivoted at their .rear ends terminating in a keyboard, a segment plate, a bail, type bars pivoted on said bailwith their lengths substantially parallel to each other and to said key levers and their widths along radial planes of said segment plate, a system of transmission linkages between said key levers and said type bars, said system including bell crank sub-levers having identical slotted arms associated with the key levers, said arms inclined forward through identical angles, terminating near the front wall of the casing, each key lever having an operator pin fitting into the corresponding slot, each said operator pin having a normal positionin said slot correlated with respect to the length of. the corresponding key lever, and the level of the type bar, so that the latter will be in platen striking position when the key is depressed. y l

2l. In a typewriting machine, in combination, a casing, a system of parallel key levers pivoted near the rear thereof and springurged to their uppermost positions, a segment plate narrower than said system, type bars pivotally supported about said segment plate 'with their lengths substantially parallel to each other and to said key levers 'and their widths radially of said segment plate, linkage lconnecting said key levers and said type bars, said linkage including bell crank` sub-levers pivoted about a common' horizontal axis near the bottom of the casing having identical arms extending forward at equal angles, with identical longitudinal slots therein curved upward at their outer ends,

` Said Sub-levers having rearwardly extending arms, with integral Shanks radiating inward from above said key levers in a common plane parallel to said segment plate, each substantially in the plane of the corresponding type bar and to substantially the level of the corresponding type bar heel, a system of parallel links `of uniform length connectinf.r the type bar heels to the outer-ends of said `sub-lever shanks, and actuating pins rigid with said key levers, each pin fitting into the associated sub-lever slot, each pin having a special initial position with respect to its associated slot, the pins on the lateral key levers being nearer the outer ends ofthe corresponding slots than thosev nearer the center of the machine, whereby the initial movement of a pin relative to the length of the corresponding slot will be at a smaller angle for the lateral than for the central keys, the angle in each case increaslng as the stroke progresses, so that the initial mechani ical advantage of operation is progressively greater from the central to the extreme lateral keys to compensate for the progressively greater friction inthe linkage corresponding to the progressively -greater inclination of the plane of movement of the` type bars, sald pins no lower-in key depressed position than the common pivot bar of the sub-levers, whereby the speed of each sub-lever and type bar will be accelerated in operation to a maximum at the end of the stroke.A

22. .The combination setforth in claim 21 in which the free end of each sub-lever shank is bent inward to substantially the plane of i lever for thetype action of a. typewriting machine, comprising a bell crank lever having its arms inclined at an acute angle and having a forward arm therein with a longitudinal slot terminating at its outer end in 'a curved vslot tangential thereto.

24. The combination set forth in claim 23 in which the continuation of the median line of the straight portion of the slot extends above the pivot of said lever.

25. In a typewriting machine, in combination, a casing, a bank of parallel `key levers terminating in a keyboard, a segment plate, a bail curved thereabout, typebars pivotally mounted uponv said bail, and an arcuate rest for the heads of said type bars, said arcuate rest extending below said bail in a plane parallel to said segment plate along an are of diameter larger than that of said bail and struck from a center higher than that of said bail for substantial uniformity of length of type bar stroke.

26. In a typewriting machine, in combination, a casing, a bank of parallel key levers terminating in a keyboard, a segment plate inclined rearward from vertical, a bail curved thereabout having the middle or lowermostportion of the arc thereof at sub stantially' the level of said key levers, type 'bars pivotally mounted upon said bail, and

a rest for the heads of said type bars extending along an arc in a plane parallel to and of diameter larger than that of said bail and struck from a center above the central perpendicular to the plane of said bail. 27 Ina typewriting machine, in combina'- tion, a casing, a bank of parallel key levers terminatingm' a keyboard, a segment plate inclined rearward from vertical toan angle .of substantially 20 degrees, a bail curved thereabout and having the middle or lowermost portion of the arc at substantially the level of said key levers, type bars of substantially standard length pivotally mounted upon said bail and an arcuate rest for the type bar heads supporting the central type bar for a range of movement thereof of substantially 95 degrees, said rest extending along an varc in a plane parallel to and of diameter greater than that of said bail struck from a center above the central perpendicular to the plane of the bail.

28. In a typewriting machine, in combination, a casing, a bank of parallel key levers terminating in a keyboard, a segment plate inclined rearward from vertical, a bail curved thereabout having the middle or lowermost portion of the arc thereof at substantially the level of said key levers, type bars pivotally mounted upon said bail, and a rest for the heads of said type bars extending along an arc in a plane parallel to and of diameter larger than that of said bail, and struck from a center above the central perpendicular to the plane of said bail, and linkage connecting said key levers to the heels of said typebars, said linkage including bell crank levers extending below and between the key levers and connecting portions to the typebar heels, extending between the key levers and below the corresponding portion of the rest.

29. The combination set forth in claim 26 in which the diiference in diameter bctween the typel bar rest and the bail is greater than the distance of the rest center above the bail center.

30. ln a typewriting machine, in combination, a casing, a standard-4bank keyboard, a system of key levers extending rearwardly therefrom and pivoted at their rear ends, a segment plate narrower than said system of key levers, a bail on said segment plate. type bars pivoted to said bail, the lowermost part of said bail being substantially at the level of the key levers, and linkage interposed between the key levers and the type bar heels, said linkage including sublevers pivoted near the bottom of the machine below the key levers and having forwardly inclined arms extending to near the front of the casing.

31. The combination set forth in claim 30 in which the segment plate is inclined rearwardly, in which the rear arms of the sub-levers extend in a plane substantially parallel to the segment plate and in which pitman links of uniform length connect the sub-levers with the type bar heels.

Signed at New York in the county of New York and State of New York this 21st day of June A. D. 1923.

LOUIS A. N-EMCOVSKY. 

